Lock-out for party-lines or extension-telephones.



up. GOOjDRUM. LOCK-OUT FOR PARTY LINES 0R EXTENSION TELEPHONES.

APPLICATION FILED DEC. 5. 1914- Patented May 30,1916.

/m ve n MW. Chm Ms L. oadmvm i a citizen of the United llll a It. M or Mr *1 a fill m "we 1 iane.

a; r r a r it may cent:

Be it lmown that l w as T1. Goonnnir, States, resi at New York, in the county of New York and State of New York, have invented cert new and usetul tor Party-Lines or Extension-Telephones, of which the follo is a clear, concise, and exact description.

This invention relates to a loch-out tor party lines or nsion telephones on twowire line its object is to give a party, when he removes his receiver in g the line, a clear circuit to the lice e from interruption by any other party'- on the se line.

The invention is of particular importance as embodied in an automatic telephone system, since it prevents interference between subscribers on party lines d the time bf selection.

The invention contemplates relay mechanism .by which the branch in use is locked dll in on the coon two-wire line and additional relay mechanism by which all the other parties on the line are cut out.

The invention in its broadest aspect is capable of various specific -embodiments, one of which is shown in the accompan drawing, by reference to which the invention may be more readily understood.

The invention is illustrated in the accompanying drawingsin. which- Figure 1 illustrates the invention as applied to the subscribers of a four party line and connected to a manual ofice. 2 illustrates the central ofice connections tor an automatic system, which may be substituted tor the manual connechions of Fig. 1.

Referring to the drag, Fig. l, d, B, G and 1D represent the subscribers stations of a tour-party line, the several subscribbranches being connected to the same twowire telephone line 1, 2. The ry mechanism for on l out the several subscribers branches is, in the present case, located at a common point and comprises a slow-acting relay 3 included in the line 2 d tour switches 4, 5, 6, 7 controlled by said relay. The branch lines are normally connected to the main telephone line by said switches.

The several party-lines are branched out from the common point represented by the relay 3, and individual to the branch or tpecttcatton at hettera Tatent.

application tiled heeemher t, ram. terial No. with.

provements in Lock-Units is as follows:

Patented May an, rare,

party-linesare the slow-release relays 8, 9, l0 and 11, respectively. I Each of said lastmentioned relays in its actuated position closes a corresponding switch 8, 9, 10 or ll, thus closing a path in parallel with the path which includes the switch 4, 5, 6 or 7,

till

respectively, and thereby loc the aetupted individual relay to the telephone line As hereinbetore stated, the invention is applicable to either a manual or an automatic telephone system. The telephone line is, therefore, shown as terminating at the central ofice in a jack 12, and cobperating therewith is shown a plug 13. At the central ofice there is also provided the usual line relay 1d, cut-0d relay and line lamp 16. The central ofifice connections for an automatic system are indicated, in Fig. 2, the line finder being indicated at 17, and the line relay 14: being provided with a contact spring 18 which controls the closure of the circuit of the starter wire 19.

The operation or the particular embodiment of the invention shown in the drawing Let it be assumed that one of the subscribers, for example, the subscriber at station 18, wishes to institute a .call. He removes his receiver from its hook,

thereby closing a circuit as follows: from battery X at the central office, through contact 20 of outed relay 15, wire 2, relay 3,

switch 5, wire 21, subscribers telephone set,

wire 22, relay 9, wire 1, contact 23 oi cutod relay 15, winding of line relay id to bat tery. Both the relays 9 and 3 are thereby energized, but the relay 9 responds more 1 quickly than the relay 3, and closes the switch 9, thereby maintaining the circuit closed through the relay 9, although the normal connection of the branch with the telephone line, through the switch 5, is opened by the energization of relay 3. The lure of sub-station B is thus locked in. The actuation of relay 3 opens the branch lines of the other stations at contacts l, 6 and 7 respectively, and hence none of said subscribers Mill can interfere with the use of the coon line by the subscriber whose line is already cut in. Y

The common relay 3 and the ind'vidual relays 8, 9, 10 and 11 are shown as inserted in the transmission circuit, but since said relays are oi the slow-rel type and may employ the : with a telephone line,

circuit, a relay individual to each subscribers I branch line, means operated by a subscriber in initiating a call which completes said initial cuit serially through the telephone line said relays and the switch controlled bythe common relay, a second circuit and means operated by the individual relay to complete said second circuit through the line and said relays when the circuit is opened at the switch controlled by the commonrelay.

2. In a telephone system, a plurality of telephone lines, a plurality of substations branched out from a common point on one of said lines, a relay in the line at said common point, a switch controlled by said relay,.

a relay individual to each subscribersbranch line, a switch controlled by and individual to each of these relays, said individual relay and said common relay being connected in series with the telephone line through the switch controlled by thecommon relay when the subscriber initiates a call, a switch operated by said individual relay, and. a second circuit completed by said switch including said line and said relays upon the opening of'the initial circuit by the operation ofthe switch controlled by the common relay;

' 3. h a telephone system, the combination of a plurality of branch normally connected to said line,

upon the initiation acommon relay, a switch controlled by said common relay, a relay individual to each subscribers branch line, a switch controlled by and individual to each of these relays, a circuit completed through one of sai individual relays and said common relayand its associated switch upon the initiation of call, and a second circuit completed throu h said individual and common relays .by t e switch controlled by the individual rela before the circuit throu h the switch 0 the common relay is opene by the operation. of said common relay.-

1-. In a telephone system, the combination with a telephone line, of a plurality of branch lines normally connected to said line, a common relay, a switch controlled by said common relay, a circuit completed through said common relay and said switch upon the initiation of a call, a relay individual to each branch line, a, switch operated by each of said relays, and a secon circuit completed by one of said individual relay switches when the initial circuit is opened at the common rela switch.

5. In a te ephone system, a plurality of telephone lines, a plurality of subscribers stations branched out from a common point on one of said lines, a relay in the line circuit at said common point, a switch cona relay individual to trolled by said relay, each subscribers branch, a circuit completed of a call through said common relay and its switch, a switch controlled by the individual relay, and a second circuit completing the operation by said last mentioned switch before said first mentioned circuit is opened at said first named switch.

In witness whereof, I hereunto subscribe my name this 3rd day of December A D.,

; CHARLES L. GOODRUM. Witnesses:

E. Eonnn, K. L. STAHL. 

